<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <title>22_布局技巧1</title>
    <style>
        .outer {
            width: 400px;
            height: 400px;
            background-color: gray;
            overflow: hidden;
        }
        .inner {
            width: 200px;
            height: 100px;
            background-color: orange;
            margin: 0 auto;
            margin-top: 150px;
            text-align: center;
            line-height: 100px;
        }
    </style>
</head>
<body>
    <div class="outer">
        <div class="inner">inner</div>
    </div>
</body>
</html>